To identify which orders can potentially be shipped together use the Mergeable filter on the Orders page. Ready To Ship orders with a matching postcode are highlighted and grouped together, making it easier to decide which orders could be shipped in the same parcel.
If you want to ship orders together we recommend adding the weight of your second order to the first when generating the shipping label. This will make sure you do not incur any surcharges by your carrier.
Once you have generated the shipping label from one order then copy and paste the tracking number into the second order and mark that as Ship without label.